Automatic turret lathe



J. C. POTTER. AUTOMATIC TURRET LATHE.

RENEWED APR. 13, 1921.

APPLICATION FILED JAN-31, 19H.

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AUTOMATIC TURRET LATHE. APPLICATION FILED JAN-31,19Il- RENEWED APR. 13, I921.- 1 Q33 Q33, A Patented 001;. 24, 1922.

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Patented 0013. 241, 1922.

RENEWED APR. 13,1921.

J. C. POTTER. AUTOMATIC TURRET LAIHE. APPLICATION 111w 11111.31, 1911. 1,438,038.

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AUTOMATIC TURRET LATHE.

APPLICATION FILED JAN.3I, 1911.

RENEWED APR. 13, 1921.

Patented Oct. 24, 1922.

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J. C. POTTER.

AUTOMATIC TURRET LATHE. APPLICATION FILED mm. 1911. RENEWED APR. 13.1w.

1,33,033, v Patented Oct. 24., 1922.

9 SHEETSSHEET 5.

q m wue'nfoz J. C. POTTER. AUTOMATIC TURRET LATHE. APPLICATION HLED JAN.31, 19H. RENEWED APR. 13,192].

Patented 00t.24,1922.

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J. C. POTTER. AUTOMATIC T URRET LATHE. APPLICATION FILED JAN-31, 19Il- RENEWED APR. 13,1921.

ma mas, Patented Oct. 24, 11922.

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AUTOMATIC TURRET LATHE. APPLICATION FIL'ED 11111.31, 1911.

RENEWED APR. I 3. 1921.

Patented Oct. 24, 1922.

9 SHEETSSHEET 8.

J. C. POTTER. AUTOMATIC TURRET LATHE. APPLICATION FILED mum, 1911. RENEWED APR. 13, 1921.

Patented Get. 24, 1922.

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JAMES CHARLES POTTER, OF PAWTUCKET, RHODE ISLAND.

AUTOMATIC TURRET LATHE.

Application filed January 31, 1911, Serial No. 605,811. Renewed April 13, 1921. Serial NO.'461,034

exact description thereof.

The object of my invention is to provide an automatic turret lathe which will fulfill the important requirements in such a machine of a wide range of work in respect of diversity of metal, variety of sizes of subjecfs, and varietyvof operations to be performed, and economical production of work. Such requirements call for great capacity as to variation of speed of spindle and of feed of tool, and for as complete automatism as is possible consistent with the avoidance of objectionable complexity of mechanism, to the end that the effort and time of the workman may be saved and thus his capacity and that of the machine for a large and satisfactory output, increased. By myinvention I provide an automatic turret lathe fulfilling the requirements noted, and I achieve this by provision for a great number of automatic changes of speed of spindle and feed of tool, and the avoidance of slow, or time-wasting motions when the tools are not cutting, and I do all this without objectionable complication of the mechanism, when the operations performed, or the results secured are taken into account. As indicative of the scope of material which these machines are required to deal with, I instance castings of iron, bronze, varieties of steel, drop forgings and the bar; as suggestive of the character of work to be performed it extends from the machining of plain work to the boring and Ea ning of subjects involving tapers, internal gt oves and recesses, and wide diversity of thread cutting; and as indicative of the scope required on the basis of the diameters to be turned or machined, some pieces may present a hole as small as five-eighths of an inch and others a diameter of twenty inches. My invention, therefore, consists in the automatic turret lathe construction substantially as hereinafter specified and claimed.

In the accompanying drawings- Fig. 1 is a longitudinal section of an automatic turret lathe embodying my invention looking from front to back;

Fig. 2 a rear elevation with nuts in section illustrating'the automatic c ange speed gearing connecting the spindle and the feed shaft;

Fig. 3 a detail view in vertical longitudinal section showing the automatic speed gear connections through the main driving shaft to the spindle;

F g. 4 an end elevation;

F g. 5 a cross section on line 5-5 of Fig. 1; I Figl. 6 a cross sectionon the line 66 of Fig. 6 is a detail view in section of certain parts appearing in Fig. 6;

- Flg. 7 a vertical section on the line 77 of Fig.5;

Fig. 3 a detail View in longitudinal section;

Fig. 9 a cross section on the line 99 of Fig. 8.

In lathes or machines of the type in which my lnvention is embodied, there are the important characteristics of the gearing together of the spindle and the tool slide so that when chan es of spindle speed take place the speed of the spindle and the feed of the tool may occur in proper time relation and the movement of the turret slide necessary for the revolution ofthe turret to change the working tool, including the time of withdrawal from the work and the return to the point where cutting is to begin, shall occur at a constant speed which is the highest permissible, so that when such movement of the turret slide takes place, the tools thereof are idle, as far as any cutting operations are concerned and it will not be affected by the rate of speed of spindle and feed during cutting operations.

A brief general description of the machine that I illustrate in the drawings to embody my invention will conduce to a readier understandin of the details 'of construction thereof. l bwer is supplied to the machine from a main driving shaft to which the spindle is geared by automatically controlled speed change gears, and from the gearing which connects the main shaft and the spindle power is applied through differential gear, also through automatically adjustable change speed gearing, to a feed shaft that is geared to the turret slide operating drum so that the feed of the turret slide is automatically variable, and there is also a gear connection from the main shaft to said feed shaft independently of the gear connection between said main shaft and the spindle and feed shaft through the differential gear, by

which said feed shaft may be revolved at the constant high speed to effect the rapid movement of the turret slideduring the period of idleness of the tools, as far as the performance of work is concerned, and said gear connection by which the feed shaft is driven from the main shaft at the constant high speed is automatically controlled.

Journaled in suitable hearings in the lower part of a frame-forming casting 10 is the main driving shaft 11 which projecting beyond the end of the frame 10 has a pulley 12 which is adapted to be belted to a coun-- tershaft or other source of power. Upon the main shaft- 11 are keyed two pinions 13 and 14. respectively, of different diameters, which mesh respectively with gears 15 and 16, also of different diameters, upon a shaft 17, each of which gears 15 and 16 at a time is adapted to be connected to the shaft 17 so that at different times the shaft 17 may be driven at different speeds. The connection between the gear 15 and the shaft 17 is of the clutch type consisting of rollers interposed between a flange on the gear and a hub keyed to the shaft so that the shaft 17 when revolved at a higher rate of speed than can be imparted to it by the gear 15 will run away from the gear, and the gear 16 is adapted, when clutched to the shaft 17 to run it at the higher rate of speed, and when the gear 16 is unclutched from the shaft 17 the shaft 17 by the automatic clutching of the gear 15 thereto is driven at the lower rate of speed. For connecting and disconnecting the gear 16 and the shaft 17 an ordinary friction clutch 18 is employed having a clutch collar 19 that is movable by means of a yoke 20 on a rock shaft 21, which as is hereinafter described, is automatically operated so as to change the gear connection between the main shaft '11 and the shaft 17. Keyed to the intermediate shaft 17 are two pinions or gears 22 and 23, respectively, that are of different diameter and which respectively mesh with gears 24 and 25'up0n a shaft 26, which gears 24 and 25 may alternately be clutched to and unclutched from the shaft 26 by the employment of clutch mechanisms similar to those I have described in the case of the gears 15 and 16 so that the shaft 26 may be driven at either of two speeds which are automatically selected or determined upon by mechanism hereinafter described which controls the operation of a rock shaft 27 having a clutch yoke 28 that engages a collar 29 of the friction clutch of the gear 25. It will be observed that the shaft 26 may be driven at any one of four different speeds, which speeds are automatically selected. One end of the shaft 26 projects outsidethe frame 10 and a change gear 30 is secured thereon which meshes with a change gear 31 on a shaft 32 supported in suitable bearings upon the frame 10 with its opposite ends projecting beyond the frame. There are connections between the shafts 32 and both the spindle and the feed shaft, and thereby is effected the gearing together of the spindle and the turret slide moving drum for the purpose of having the changes of speed of spindle and feed of tool occur in proper time relation. The spindle 33 having a chuck 34 is journaled in hearings in the head stock 35 that is mounted on the top of the frame 10, and the gear connection between the shaft 32 and the spindle 33 includes a gear 36 on the shaft 32 meshing with a gear 37 on a shaft 38 above the shaft 32, a gear 39 upon the shaft 38 meshing with a gear 40 upon a shaft 41 situated between the spindle and the shaft 38, and a pinion 42 on the shaft 41 which meshes with a gear 43 bolted to the chuck 34. The pinion 42 is loose on the shaft 41 and a clutch 44 operable by a hand lever 45, is provided, so that at will the spindle maybe disconnected from driving connection with the shaft 41 Besides the automatic changes of speed of spindle. which, as I have explained, enables the spindle, to be run at four different speeds. other spindle speeds may be secured by the hand change gears 30 and 31.

The feed shaft 46, or the shaft through V which connection is made to drive the turret drum, is preferably located at the back of the machine, and the gearing by which various feeding speedsmay be imparted to said shaft 46 from theshaft 32, is best illustrated in Figures 2 and 3. On the shaft 32 there are three gears 47, 48 and 49, which respectively, through intermediate gears,

mesh with gears 50, 51 and 52, keyed to three concentric shafts 53, 54 and 55, respectively, supported in hearings on the frame 10 at the rear of the machine! Keyed to the shaft 53 to which is fixed a gear 50, are two gears 56 and 57 of different diameter which respectirely mesh with gears 58 and 59, also of different diameter, loosely mounted upon a shaft 60 below the shaft 53 and fixed to the shaft 54 of the gear 51. is agear 61 which meshes with a gear 62, also loose on the shaft 60, and fixed to the shaft 55 is a gear 63 which meshes witha gear 64, also loose on the shaft 60, so that there are four gears 58, 59, 62 and 64, loose on the shaft 60 and which are of difierent diameter, and each of whlch four gears at a time may be clutched to or connected with the shaft 66 so as to re volve the same, and, of course, revolye it at four different speeds, which speeds are automatically selected as hereinafter explained. Besides the automatic changes of feed, changes may be made by the hand change gears 50 and 52, the change gear 52 being especially useful for varying the feed for reaming and threading.

Whatever may be the selected speed of the shaft 60, it is transmitted for tool feeding purposes tothe feed shaft 46-through a pinion 65 keyed to one end of the shaft 60, and 1 gear- 66 keyed to the pinion carrier 67 of the differential gear 68 on the feed shaft 46 so that all feeding speeds are transmitted to,

the shaft 46 through the differential gear, an arrangement which results in simplification 0f the gearing required in my machine and possesses a desirable practical advantage in "that the big reduction incident to the use of the differential gear calls for but little power in transmitting motion from the c ange gears on the shaft60.

The shaft 60 is tubular or hollow, and longitudinally slidable therein is a rod or plunger 69 in which are mounted two radial slidable keys 70, each key being normally pressed outward by a spring 71 into a radial slot 7 2 slightly longer than the portion of the shaft 60 encircled by the change gears 58, 59, 62 and 64: and each of said change gears has a radial slot 73 adapted for the reception of the outer end of one of the keys so as thereby to lock or clutch the gear to theshaft 60. The two keys 70 are spaced apart a distance greater than the distance apart of two adjacent change gears so that only one of the keys 70 at a time may engage one of said change gears. the other key 70 at such time being midway between two adjacent change gears and engaged by the inner circumference of a collar or washer 74 lying between adjacent gears so as to prevent the entrance of said collar engaged key into the slot 73 of a change gear. Each key 70 has on its opposite edges inclined or beveled shoulders so that they will ride under the collars or washers 74. It will be seen that by the construction and arrangement of the keys 70, less longitudinal movement of the key carrying rod or plunger 69 is required than would he the case if a single key 70 was employed which must traverse through the entire series of four change gears. The mechanism for the automatic movement of the key car rying rod or plunger 69 is hereinafter described.

The constant high speed is imparted to the feed shaft 46, to effect the rapid return and advance of the turret slide up to the cutting point, by a train of gears that directly connect the main driving shaft 11 and the feed shaft 46 so that the movement of the turret slide for the return and revolution of the turret and the advance. is effected wholly independent of the speed of the spindle or the gearing for varying the feed speed of the shaft 46. Said train of gears includes a gear wheel 75 keyed to the main driving shaft 11 and a gear 76 loose on the feed shaft 46 and adapted to be automatically clutched to and unclutchedtherefrom by a clutch collar 77. The gear 76 is slidable into and out of engagement with the clutch collar 77 for Patent which purpose its hub is engaged by a yoke 78 on a rock shaft 79 to which movement is automatically imparted at the predetermined time as is hereinafter described.

Of course, any type of turret drum may be employed, and suitably geared to the feed shaft 46, although the turret drum 80, f illustrate. is of novel construction, having a helical groove 81 which engages theturret slide stud 82 on the underside of the turret slide 83. For revolving the drum it is provided at one end with a gear wheel 160 with which meshes a pinion 170 on a shaft 180, which may be driven either in one direction or the other through gears 190 and 200, respectively. This novel form of drum or turret slide o ierating means forms the subject of 0. 1,040,751, issued Oct. 8, 1912, and, therefore, in view of the general description which I have just given need not be more fully described herein.

Taking up now the description of the mechanism by which automatic changes of spindle speed and turret slide feed may be accomplished, said mechanism will be found best illustrated in Figures 1. 6, 7, 8 and 9.

It will be recalled that the clutch collars 20 and 29 on the shafts 17 and 26 for controlling the speed of said shafts and hence the speed of the spindle are respectively operated by rock shafts 21 and 27. Keyed to the rock shaft 21 is a crank arm 85 having a crank pin or stud engaging a cam 86 on a shaft 87 and the rock shaft 29 has a similar crank arm 88 whose crank pin or stud engages a cam 89 on said shaft 87 so that by the revolution of said shaft 87 the crank arms 85 and 88 will be rocked and thus the gear connections of the shafts 17 and 26 automatically change to vary the speed thereof. The cams 86 and 89 are loosely mounted on the shaft 87 and they rotate with the shaft 87 only when permitted so to do. A friction clutch is provided for each cam that in each instance consists of a conically recessed member or flange 90 keyed to the cam and a conical friction head 91 fixed to the shaft and yieldingly held in frictional engagement with the member 90 by a coil spring 92 so that in the absence of means to prevent the rotation of the cams they revolve with the shaft 87. Keyed to the hub of the cam 86 is a sprocket wheel 93 from which a sprocket chain 94 runs to a sprocket wheel 95 on a horizontal shaft 96, and keyed to the hub of the cam 89 is a sprocket wheel 97 connected by a sprocket chain 98 with a sprocket wheel 99 on a horizontal shaft 100 parallel with the shaft 96. The shafts 96 and 100 are geared together by intermeshing gears 101 and 102 so that a common controlling mechanism may answer for both shafts, said controlling mechanism holding the shafts 96 and 100 from revolving and thus preventing revolution of the cams 86 and 89 until the selected times for the revolution of said cams 86 and 89. Said controlling mechanism is best illustrated in Figures 6, and 7 and it consists of a drum 103 which is keyed to the shaft 100 and has radially projecting pins or studs 104 on its periphery, there being four such pins or studs 104 and located so as to travel in different circular paths. Below the shaft 100 is a box 105 having a series of vertically movable pins 106 extending in aline parallel with the axis of the drum shaft 100, each of said pins 106 being situated in alignment with the circular path traveled by a stud or pin 104 so that if a pin 106 be moved verti cally to place its upper end in the path traveled by a stud or pin 104, the latter will encounter said p-in 106 and thus the drum 103 and the shafts 96 and 100 be restrained from rotation until said pin 106 is withdrawn from the path of the stud 104 that it engages.

Each pin 106 is normally pressed down out of stud-engaging position by a coil spring 107, and it is supported or held in stud-engaging position by means of a horizontally movably spring-pressed latch 108 that en-' gages a shoulder formed by a notch 109 in the side of the pin 106. At its lower end each pin 106 protrudes beyond the box 105 and has a beveled nose 110 adapted to be engaged by a dog 111 secured adjustably to the periphery of a wheel 112 WlllClllS'TlIOllIll'Bd on a shaft 113 that is geared to and receives motion from the feed shaft 46. The pins 106 are lifted into stud-engaging position by the action of dogs 111 so that it will be seen that the presence or absence of the dogs on P the dog wheel, and the particular circumferential position of the dogs on the dog wheel, determine the change of speed of the spindle. If a change of speed of the spindle is to take place, it is effected by the action of a dog 111 upon a lowered pin 106 which being lifted cams rearward, the latch 108, which is common to all four pins, and permits the already raised pin 106 to fall, thus freeing the pin carrying drum and permitting the shafts 96 and 100 to revolve, and the pin 106 thus raised will be latched in a raised position by the forward movement of the latch 108 and its upper end interposed in the path of one of the drum studs 104 so as to bring the drum and the shafts 96 and 100 to a stop. There are four studs or projections 104 so that two are provided for each cam 85 and 89, each of said cams having two positions, one for throwing its clutch out of engagementand the other for throwing its clutch into enga meant.

he reciprocationof the rod or plunger 69 for changin the connection. of the change gears 58, 59, 6'3 and 64 on the shaft 60 for chang ng the d of the feed shaft 46 is 7 11m: control of have ins.

head 119 pressed in frictional contact by a' spring 120- with a' correspondingly shaped flange 121 on the side of a gear 122 which is keyed to the shaft 87 and with which meshes a pinion 123 on the main driving shaft 11 so 'as to transmit motion to the shaft 87. On the hubiofcam 114 is a sprocket wheel 124 connected by a. sprocket 125 to a sprocket wheel 126 on a hollow. shaft or sleeve 127 loose on the shaft 100, and secured to said sleeve 127 is a drum 128 carrying radially projecting pins or studs 129 similar to the drum studs 104 and which are adapted to co A operate with a series of pins 130 similar to the pins 106 in the latch box 105, said pins 130 being under the control of dogs 131 adjustably secured to the periphery of a dog wheel 112.

In setting the machine for work it may be desirable to change the speed of the spindle or the feed of the tools, and to enable these changes to be made by hand conveniently, I provide for each pin 106 and 130 a hand operating device which includes a rod 132 extending to the front side ofthe machme where it has a knob 1 33 and at its inner end is pivoted to abell crank lever 134, one arm of which'engages a'-notch in the side of the Besides using the single dog wheel 112 to automatically effect changes of speed and feed, I also utilize said dog wheel by applying thereto dogs -135 to automatical y throw the clutch by which the gear 76 is cdnnected to the feed shaft 46 for driving said feed shaft at the constant high speed direct- 1 from the main driving shaft 11. It will, therefore, be seen that all the automatic changes are accomplished from the single dog wheel 112.

Having thus described my invention wha'; I clainris- 1. In an automatic turret lathe, the combinat-ion of a work spindle, rotatable at different working speeds, a turret reciprocating: cam, a feed shaft operatively connected with said cam,a shaft having a gear connection with the spindle and also with the feecl shaft, the feed shaft connection comprising a differential gear acting on the feed shaft, including variable speed mechanism gears? to the differential gear so as to apply feed l= ing power at different speeds in relation t-c the spindle speed through the differential gear to the feed shaft, a main driving shai, from which the spindle and shaft ceive their revolutions for peril icing worf;

and a gear connection directly from the main driving shaft to the feed shaft adapted to revolve the latter at a constant speed.

2. In an automatic turret lathe, the combination of a work-spindle, a main driving shaft, an intermediate shaft geared to the spindle, variable speed gearing connecting the main driving shaft and said intermediate shaft, a feed, shaft, a difierential gear acting on the feed shaft, a gear connection between the intermediate shaft and said difierential gear comprising two shafts, each having a series of graduated gears, the gears of one shaft meshing with those of the other, automatic means to render a pair of meshing graduated gears operative at a time, a turret reciprocating cam, and an operative connection between the feed shaft and said cam.

3. In an automatic turret lathe, the combination of a work spindle, a driving shaft, and an operative connection between the driving shaft and the work spindle, comprising two intermediate shafts having each two gears of difi'erent' diameter loose thereon, automatic meansto operatively connect one of said two gears to its shaft at a time, and two gear connections of different speed. be tween the intermediate shaft next to the main driving shaft and the two loose gears on the second intermediate shaft, a feed shaft, a gear connection between the said second intermediate shaft and th' ffl shaft, a gear connection directly from the main driving shaft to the feed shaft whereby the latter may be revolved independently of variation of speed of the spindle, and a turret reciprocating cam operatively connected with said feed shaft.

4. In an automatic turret lathe, the combination of a spindle, a turret slide, a driving shaft, a series of gears to which motion from said driving shaft may be transmitted, a shaft common to said series of gears, and

automatic means to clutch one of said gears at a time to said shaft, including a constant- 13: revolving shaft, a rotatable element, a friction clutch between said shaft and said rotatable element, and automatically released means that prevents rotation of said element.

5. In an automatic turret lathe, the com bination of a turret slide, a main driving shaft, a power transmitting connection between the main driving shaft and said slide comprising a shaft to be driven from the main shaft at different speeds, gearing between said shafts and speed-changing mechanism comprising a constantly revolving shaft, a rotatable element, a clutch for operatively connecting the shaft and said element, and clutch operating means.

6. The combination of a spindle, a turret slide, a driving shaft, a series of gears to which motion from said driving shaft may be transmitted, a shaft common to said series of gears, and automatic means to clutch one of said gears at a time to said shaft, including a constantly revolving shaft, a rotatable element, a clutch between said shaft and said rotatable element, means to prevent rotation of said element. and automatic means that control said rotation preventing means.

7. In an automatic turret lathe, the combination of a turret slide, a main driving shaft, a power transmit-ting connection be tween the main driving shaft and said slide comprisin a shaft to be driven from the main shaft at different speeds, gearing between said shafts and speed-changing mechanism comprising a shaft, a cam, a lever actuated by the cam, a clutch for operatively connecting the shaft and said cam, and a clutch operating means.

In testimony that I claim the foregoing I have hereunto set my hand.

JAMES CHARLES POTTER.

IVitnesses JOHN JOHNSTON, EARLE ROBERTS. 

